Single frequency laser multiple feedback effects based onray tracing method

A ray tracing model of multiple optical feedback with asymmetric plane-concave cavity was presented. With this model, the generation mechanism of highresolution fringes in single frequency laser multiple feedback was elaborated. Also, the affecting factors of fringe-shape were analyzed, including tilted angle, curvature, reflectivity of feedback mirror and length of external cavity. In addition, the effective feedback order and coupling efficiency of feedback beams with different tilted angles were obtained. Theory analysis and experimental results show that the high-resolution feedback fringes without envelopment can be obtained when the tilted angle is 1.7. In particular, the resolution of feedback fringes can be /50, which is very important to explore high-precision displacement measurement system.